Molding of hollow parts is a continuous need for plastic industry. In particular, consumer goods are usually packed into plastic hollow parts which are produced by injection molding. In addition, most of the small electronic appliances are also housed in injection molded plastic hollow parts. Thus, there exists a continuous need in industry to form plastic hollow parts of several forms and functions. Complex forms of the plastic objects require complex mold cavities. The more complex is the plastic object to be formed the more mold parts are usually needed. As a consequence molding devices become larger in order to meet the geometric requirements of the complex molds. Said problem increases if multilayer plastic objects shall be formed or undercuts are needed in the plastic object. EP0894604A1, DE102010033675A1, JP61049808A and EP2159031A1 disclose multi-layer injection molding devices with several molding stations which uses cavity extension elements in addition to mold halves for forming the mold cavities in order to combine design flexibility and multi-layer molding. Further, the pre-molded parts are transferred between the different molding stations. However, these devices are still complex. Thus, there exists a continuous need to reduce complexity of molding devices by containing the design flexibility of the molded parts. Thus, it is an object of the molding device described herein to produce complex plastic objects with minimal mold parts and small geometric dimensions.